Restoring hedgerows for wildlife
Hedgerows are vital habitats that help many species survive but for the last 70 years they have been in decline. Now, their importance is well understood and the National Trust is revitalising and re-establishing these valuable and diverse habitats.
Besides their role in marking field boundaries and enclosing livestock, hedges provide important shelter and nesting sites for numerous species of animals, including birds, insects and mammals. They are nature's larder, with pollen, nectar, berries, nuts and seeds through the seasons.
Managing mature hedgerows
Mature hedgerows can be found across our Chilterns countryside sites, but the main concentration is on the Bradenham Estate where the species-rich habitats teem with wildlife. The combination of tall, wide hedges with a wide field margin and hedgerow trees provides one of the best types of farmland wildlife habitats it is possible to achieve.
The National Trust rangers and volunteers, together with the tenant farmer, manage the hedgerows by working with the natural life cycle they go through as they mature. They are carefully and gently trimmed each year on just one side and are slowly allowed to develop and rejuvenate, to guarantee their long-term success.
Hazel hedges are being coppiced to develop habitats for invertebrates and for mammals like the dormouse, which overwinters in the leaf mould that accumulates within the multi-stemmed base of the hazel stool.
Some of the hedgerows contain up to 15 woody species including hawthorn, hazel, spindle, wayfaring tree and elder, and are up to 10 metres wide reflecting their great age. They are rich in bird life, especially songbirds such as yellowhammers and corn buntings, as well as the more familiar robins, blackcaps, greenfinches and goldfinches.
New hedgerow planting
At Hughenden Manor, the rangers and volunteers are focusing on establishing new habitats to enable native and endangered species to thrive. The estate has red-listed farmland bird species including skylark, grey partridge and yellowhammer. To provide the right habitat for these birds, the rangers are reinstating hedgerows that had once been on the estate during Disraeli’s time. The new hedges, most of which have been planted at Manor Farm, include hawthorn, field maple and hazel.
The new hedges will provide song posts, shelter and nesting opportunities for both woodland and farmland birds; while nectar, berries, nuts and leaves will soon provide food for a wide assortment of creatures. For example, hawthorn's spring blossom and autumn berries attract both pollinating insects and many species of bird, and the thorny branches create secure nesting sites for small birds in the spring.
Corridors for wildlife
Hedgerows also serve as important wildlife corridors as they link together fractured ancient woodlands enabling animals to safely roam under cover from one wood to another. These vital corridors are essential for connecting what would otherwise become increasingly isolated and vulnerable pockets of wildlife.
Some smaller species of mammal, such as voles, field mice and shrews, will not cross open areas for fear of being taken by predatory birds such as tawny owls, kestrels and buzzards. The hedgerows will provide them with vital cover.
The history of hedgerows
The planting of hedgerows to enclose agricultural land started well before Roman times, although the process of ‘enclosure’ became a widespread feature of the English rural landscape during the 15th and 16th centuries and continued through to the mid-18th century when the Enclosures Act prompted a great spurt in hedge planting. This led to what many regard as the definitive ‘checkerboard pattern’ of the rural English landscape with which we are familiar.
The removal of hedgerows is not a new phenomenon. Many were lost during the Napoleonic Wars in the early 19th century to increase agricultural output when a besieged Britain was threatened with starvation. And after the Second World War the government actively encouraged hedgerow removal. This was to ensure that Britain was self-sufficient in food by using large scale agricultural machinery and it was not suited to small fields bordered by hedges. Other hedgerows have simply been neglected, becoming ‘gappy’ lines of mature trees, while some are heavily ‘over-trimmed’ without taking into account the natural lifecycles of hedgerow species.
From On a Lane in Spring by John Clare (1793-1864)
A little lane - the brook runs close beside;
And spangles in the sunshine, while the fish glide swiftly by;
And hedges leafing with the green springtide;
From out their greenery the old birds fly,
And chirp and whistle in the morning sun;
The pilewort glitters 'neath the pale blue sky,
The little robin has its nest begun
When John Clare described the hedges in a country lane in spring in the 19th century, hedgerows were commonplace, but their importance as vital refuges and corridors for wildlife was largely overlooked.
Hedges also play a major role in preventing soil erosion by stabilising the soil, and on slopes they help to prevent soil creep and to reducing the leaching of plant nutrients from the soil. And like woodlands they help to regulate water supply and reduce the risk of flooding.
Their importance is now well understood and the National Trust is revitalising and re-establishing these valuable and diverse habitats, thanks to the support of members, visitors and donors.